National districts or national raions (Russian: Национальные районы) were special raions (administrative units) of the Soviet Union from 1924 up until the 1940s, created to meet the needs of minority ethnic and cultural populations within republics.
They were part of the larger policy of korenizatsiia, or "indigenization" pursued during this time.
[1] The Soviet Russia that took over from the Russian Empire in 1917 was not a nation-state, nor was the Soviet leadership committed to turning their country into such a state.
In the early Soviet period, even voluntary assimilation was actively discouraged, and the promotion of the national self-consciousness of the non-Russian populations was attempted.
Each officially recognized ethnic minority, however small, was granted its own national territory where it enjoyed a certain degree of autonomy, national schools, and national elites.